diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index 52048ca79f9..aa313a526c1 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -1018,7 +1018,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // #2 (region bounds). let principal_def_id_a = a_data.principal_def_id(); let principal_def_id_b = b_data.principal_def_id(); - if principal_def_id_a == principal_def_id_b { + if principal_def_id_a == principal_def_id_b || principal_def_id_b.is_none() { // We may upcast to auto traits that are either explicitly listed in // the object type's bounds, or implied by the principal trait ref's // supertraits. diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index cc5c7532b50..0ba3b4e6e55 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -1153,6 +1153,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`. let iter = data_a .principal() + .filter(|_| { + // optionally drop the principal, if we're unsizing to no principal + data_b.principal().is_some() + }) .map(|b| b.map_bound(ty::ExistentialPredicate::Trait)) .into_iter() .chain( |